Large national biomonitoring studies are reporting nearly universal exposure to numerous environmental contaminants in the US population, including Bisphenol A, raising the question of how exactly people are being exposed. Identifying the actual sources of exposure to chemicals that are ubiquitous in our environment is fundamental to the development of strategies and policies that will effectively reduce and prevent harmful exposures. Our understanding of human contact with environmental sources of exposure is inadequately characterized and thus we do not know which sources or behaviors are producing the chemical body burden that we discover through biomonitoring studies. This pilot study is designed to provide original research on potential sources of exposure to BPA and to help resolve the current debate regarding the biological half-life of BPA and to provide critical insights into potential sources of fetal exposure to BPA, a lifestage at high risk. To achieve these aims, we will develop and implement a questionnaire on dietary intake of potentially BPA contaminated foods and beverages. We will analyze the relationship between questionnaire data and levels of BPA measured in biological specimens from pregnant women to identify key sources of exposure. We will also explore and account for previously reported relationships between BPA exposure and such socio-demographic factors as age, ethnicity and socio-economic status. We will compare levels of BPA in maternal specimens collected during non-fasting and fasting conditions to characterize the clearance and biological half life of BPA in pregnant women. This study addresses data gaps in our knowledge of how humans are exposed to BPA - a key piece of information for reducing and preventing exposures. It will also provide valuable insight regarding the biological half-life of BPA. This informaiton will contribute to efforts toward prevention of exposures and will contribute new tools to future epidemiologic studies.